Typically, communication equipment includes a backplane coupled between a plurality of line cards and one or more timing sources for providing clock signals to the plurality of line cards. To prevent system failures, the communication equipment often includes both an active timing card and a redundant timing card coupled to the plurality of line cards over the backplane. In operation, the active timing card acts as the timing master and generates clock signals that are distributed to the line cards in the communication equipment. These clock signals are distributed between and phase aligned across the line cards in the system over the backplane connecting the line cards to the active timing card.
Current and anticipated communication system require precise phase alignment within the egress and ingress ports of communication equipment. Current solutions known in the art employ static propagation delay compensation to align the clocks across the line cards. However, static propagation delay measurements, which are applied at the initialization of the timing device, are unable to compensate for temperature delay variations of the communication system over time, therefore making it difficult to meet the required precise phase alignment requirements of the egress and ingress ports of the communication equipment.
Accordingly, what is needed in the art is system and method for improved clock phase alignment at a plurality of line cards over a backplane of a communication system.